Compounds , elements and mixtures Flashcards
(28 cards)
what is a compound
a substance made up of 2 or more different atoms chemically combined
What is an element?
A substance that cannot be broken down into simpler substances by chemical means.
True or False: A compound is made up of two or more elements that are chemically bonded together.
True
Fill in the blank: The smallest unit of an element is called a ___.
atom
What is a mixture?
A combination of two or more substances that are not chemically bonded.
Which of the following is a characteristic of compounds? (A) They have a fixed composition. (B) They can be separated by physical means. (C) They are always homogeneous.
A and C
What is the difference between an element and a compound?
An element is a pure substance made of one type of atom, while a compound consists of two or more different types of atoms chemically bonded.
True or False: All mixtures are homogeneous.
False
What type of mixture has a uniform composition throughout?
Homogeneous mixture
What type of mixture does not have a uniform composition?
Heterogeneous mixture
Fill in the blank: A ___ is a substance that can be decomposed into simpler substances by chemical reactions.
compound
What do we call the chemical combination of two or more elements?
Compound
True or False: Salt (NaCl) is an example of a compound.
True
Which of the following is an example of an element? (A) Water (B) Oxygen (C) Sugar
B
What is the main component of air?
Nitrogen
Fill in the blank: The process of separating a mixture using physical methods is called ___.
filtration
What is the chemical formula for water?
H2O
True or False: Mixtures can be separated into their components by physical means.
True
What is the term for a pure substance that cannot be separated into simpler substances?
Element
Which of the following is a characteristic of homogeneous mixtures? (A) They have a variable composition. (B) They appear the same throughout. (C) They can be easily separated.
B
What is an example of a heterogeneous mixture?
Salad
Fill in the blank: A ___ consists of two or more elements chemically bonded in a fixed ratio.
compound
What is the main difference between a compound and a mixture?
Compounds are chemically bonded, while mixtures are not.
True or False: All compounds are made up of elements.
True
